Plus there’s always the incense trick. Light a stick, move it to various places around the door’s frame, let the smoke indicate where the drafts are.
That’s a damn good idea! 
Wish I had thought of it. :smack:
I sure won’t forget it.
I first saw it used when an inspector was checking a house my girlfriend was buying. He sealed the doors, put in an heavy fan to exhaust air from the house (thus creating negative pressure within) and wandered around with an incense stick, checking window and door frames, electrical outlets (which can be surprisingly drafty) and whatnot. I was amused, and he explained that some inspectors use elaborate smoke machines, but the incense was a lot cheaper and smelled a lot better.
(bolding mine)
Now there’s a man with a little “horse sense”.
FWIW, even though I’ve been in the construction industry for over 30 years, I’m still learning little “tricks of the trade”. (not so often now, though ;))
One thing I have to admit is… I’ve learned more than a couple of 'em right here on the SDMB. 
Sorry, didn’t get back to the Board until today.
A knife blade shows that most of the crack is accounted for by carpet & thr stuff the carpet is on.
The crack is about 3/4 inch deep near the side it opens on, though.
Meet my Wet Trout.
<SLAP>
Are the windows double-paned or just big single sheets of glass? You say the doors are from the 50s/60s - are the windows that old too?
You could be losing heat through the windows themselves, too. And even in the joints between the windows and doors.
A window insulator kit would solve that part of the draftiness and you’d be able to continue using the doors.
Double paned.
And the kits seem to be a way to seal off the windows completely, which I don’t wanna do, & might be against the condo rules anyway.
Well, the sealing kits aren’t permanent, you can peel them off in the spring.
I assume with your sliding glass doors you have 2 big windows next to each other, one of which is a sliding door, right?
You would use the kit to seal over the two windows (one of which is a door) separately. Put the double-sided tape on the frame around each window/door and then put one sheet of cut plastic on each window/door and seal out the draft.
If you put the tape on the frame that holds the entire window/door unit (the sash) and then used one sheet of plastic to go over both windows (one of which is a door) then yeah you’d be sealing the thing off completely. But in this instance you’d be keeping the cold air out that comes through the glass itself.
You’d still have two separate windows (one of which is a door) and would still need to address any seams with caulk or weather-stripping, but at least you would be minimizing the air coming through the glass.
I’m wrong.
***Not *** double paned.
Single only.
Now I know why it is so cold in winter.
Not counting the window-sealing-off stuff, is there an insulating, clear coating for windows?
Hmmm…this might work.
(bolding mine)
FWIW, I live in a house that was built in 1930. Most of the windows on the ground floor are ‘double hung’ units, (the top and bottom portions both, are movable) that are 3’6" wide x 6’6" tall, and consist of 20 small single panes of glass. That’s a considerable amount of glass, which equates to a lot of thermal energy going in the direction that you don’t want it to go. 
What I’m getting at is, quite a few years ago I installed exactly the type of barrier that ZipperJJ has described. I was a tad bit skeptical of the stuff at first. :dubious:
Granted, I live on the Gulf Coast (Houston, Tx) and it doesn’t get all that cold, (We won’t discuss the only other season, we have here. ;)) but all of that single paned glass does make a difference.
My skepticism is (was) unwarranted, especially after the first years heating/cooling bills were compared to the previous.
It DID make a difference (summer and winter). YMMV
The only negative thing that I can say about it is, you might incur a certain amount of condensation on the glass. It depends on the temperature difference between inside and outside. (Although I’m sure you’re already aware of the possibility of that occurring.)
ETA: If put on correctly it doesn’t distort the view very much at all, if any. And IIRC, the cost was minimal as was the amount of ‘technical skill’ needed to install it.
(bolding mine)
FWIW, not that I’m aware of.
It certainly sounds like a viable alternative.
IMHO, it can’t hurt and it’ll probably help.
ETA: Great idea ZipperJJ, I had completely forgot about that method! :smack:
My repair ideas are on hold, due to family issues.
I’d rather do this, but I gotta do that.
I know that ‘tune’ well! 
You can pick your nose. You can pick your friends. Hell, you might even be able to pick your friends nose, if you ask nicely.
But you can’t pick your kinfolk! 